Редактирование: Molecular manufacturing (раздел)

= Criticism =

== Richard Smalley ==

== Richard Jones ==

== George Whitesides ==

== RationalWiki ==

The opening quote, 

<blockquote>''Drexler’s thesis is merely the source of the disease. What I’m really sick of are ding dongs trying to tell me toothpaste or golf balls is nanotech.''</blockquote>

is actually correct, since it was Drexler who first started the hype with ''Engines of Creation'', a book that later proved to be much more abstract and fantastic than his more down-to-Earth work on the chemistry of mechanosynthesis. It is true that Drexler's thesis is the 'source of the disease', for his ideas where bandwagoned from the start. The second sentence is something we can all share.

<blockquote>The idea was first postulated by Richard Feynman and popularised by the work of science fiction that Eric Drexler used as a Ph.D. thesis. Nanotechnology fanboys — as opposed to the people who actually work with the stuff — have a habit of downplaying Feynman's origination of the idea and playing up Drexler, possibly because the latter is far more indulgent of their fantasies.</blockquote>

The first part needs a correction: Drexler's thesis is okay, it's ''Engines'' that's the problem. Compare the predictions he makes in ''Engines'' to the machines he discusses in ''Nanosystems'', and you'll see a large gradient between the fantasy of the nano-future and the actual simulations and calculations.

The rest is just all ad-hominem so there really isn't much to disprove. Drexler's thesis is available online, and I have yet to see someone find an error in Nanosystems, besides the diamond surface friction calculations which came from simple scaling law analysis (With considerations for the nanoscale). The individual, atomically-precise machines (The small bearing, the planetary gear) were 'validated' by molecular dynamics. Validated in quotes because force fields are cool and all but it is improper to use anything less than quantum chemistry as proof of.

<blockquote>In the woo world (i.e., science fiction), nanomachines will be able to repair a body from almost complete mush into a fully functioning human.</blockquote>

Reviving cryonics patients through nanotechnology is one aspect of Freitas' work on nanomedicine that may not be feasible. Cells, unlike ordinary machines, do not shatter into discrete components that can be glued together, and it may be overkill to use nanomechanical arms to repair cells, a process which will quite probably be easier to achieve through biological means. They refer to the state of cryopreserved patients as 'mush', which shows they really are just trendy pseudo-skeptics: [[Cryonics#Evidence|Cryonics works]]. As for revival, see [[Cryonics#Revival|the relevant section]].

<blockquote>The popular conception of nanotechnology is K. Eric Drexler's concept of nanobots, like industrial robots scaled down a billion times. This is entirely made of bollocks and would violate physics, chemistry, and thermodynamics.</blockquote>

All Drexler talked about were nanoscale robot arms.

[[File:Drexler_Arm_detail.jpg|thumb]]

As for violations of physics, chemistry and thermo: The last item refers, probably, to the idea that a 'self-replicating nanobot' (A term created by the nonsensical bandwagon that spawned from ''Engines of Creation'') would essentially burn due to the waste heat of rapid self-replication. Though nobody has actually done the math I bet it would be a problem. Thankfully, Drexler's vision of nanotechnology is not about self-replicating nanobots, so we can skip that.

As for chemistry, well, we'll probably be hearing Richard Smalley's arguments against molecular manufacturing, [http://www.imm.org/publications/sciamdebate2/smalley/ so I'll just let Ralph Merkle refute those].

Now, notice the sources of the statement: The first is an article by Richard Jones, a critic of Drexler's vision of nanotechnology (Who's still cool though). However, he has said that he does not think it's impossible, and he says, answering the question "Does Nanosystems contain obvious errors that can quickly be shown to invalidate it?"

He replies: "No. It’s a carefully written book that reflects well the state of science in relevant fields at the time of writing. Drexler’s proposals for radical nanotechnology do not obviously break physical laws. There are difficulties, though, of two types. Firstly, in many cases, Drexler used the best tools available at the time of writing, and makes plausible estimates in the face of considerable uncertainty. Since then, though, nanoscale science has considerably advanced and in some places the picture needs to be revised. Secondly, many proposals in Nanosystems are not fully worked out, and many vital components and mechanisms remain at the level of “black boxes”." For a shorter explanation, he does not think it's impossible, merely pushing against the grain, and in this we can all sort of agree. The second link is a blog that repeats essentially the whole thing. The only technical point that is correcet is that Drexler's machines '[look] rather like a meter-scale object', which is related to Jones' earlier point.